Neural alpha oscillations index context-driven perception of ambiguous vowel sequences

• Published in: iScience Vol. 26; no. 12; p. 108457
• Main Authors: Alain, Claude, Göke, Katharina, Shen, Dawei, Bidelman, Gavin M., Bernstein, Lori J., Snyder, Joel S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.12.2023; Elsevier
• Subjects: Audiology; Behavioral neuroscience; Linguistics; Sensory neuroscience; Linguistics; Sensory neuroscience; Behavioral neuroscience; Audiology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2023.108457

Perception of bistable stimuli is influenced by prior context. In some cases, the interpretation matches with how the preceding stimulus was perceived; in others, it tends to be the opposite of the previous stimulus percept. We measured high-density electroencephalography (EEG) while participants were presented with a sequence of vowels that varied in formant transition, promoting the perception of one or two auditory streams followed by an ambiguous bistable sequence. For the bistable sequence, participants were more likely to report hearing the opposite percept of the one heard immediately before. This auditory contrast effect coincided with changes in alpha power localized in the left angular gyrus and left sensorimotor and right sensorimotor/supramarginal areas. The latter correlated with participants’ perception. These results suggest that the contrast effect for a bistable sequence of vowels may be related to neural adaptation in posterior auditory areas, which influences participants’ perceptual construal level of ambiguous stimuli. [Display omitted] •Perception of an ambiguous auditory stimulus is influenced by prior context•Listeners report hearing the opposite percept of the one heard immediately before•Prior context modulates stimulus-evoked alpha power in angular and supramarginal gyrus•Alpha Power correlates with listeners’ perceptual construal level of ambiguous stimuli Audiology; Behavioral neuroscience; Sensory neuroscience; Linguistics